code: def forward(self, xb):
      return self.model.train_step(data_batch=xb, optimizer=None)
  
file_path: icevision/icevision/models/mmseg/fastai/callbacks.py
imports: from icevision.imports import *
  from icevision.utils import *
  from icevision.core import *
  from icevision.data import *
  from icevision.engines.fastai import *
  from icevision.models.mmseg.utils import *
  from icevision.models.mmseg.common.prediction import convert_raw_predictions
label_desc: Use image node_id 2 for calling the _ModelWrap obj's underlying member method code with example usage: obj.forward(xb) and returns: self